This document discusses mercury use in dentistry and its risks. It covers the history of dental amalgam, forms of mercury exposure including vapor release from dental fillings, and health effects like neurological and renal toxicity. Regulations for mercury in dentistry are outlined, such as the OSHA exposure limit. The document also describes managing mercury spills and proper disposal of dental waste containing mercury.
A comprehensive lecture comparing the Types, Properties and Clinical applications of different types of artificial teeth used in denture making.
For more lectures on Dental materials follow Dr Rashid Lectures on Dental Materials on Facebook (dmbydrrashid)
Remineralization is defined as the process whereby calcium and phosphate ions are supplied from an external source to the tooth thereby, causing ion deposition into crystal voids in demineralized enamel, thus producing net mineral gain.
Remineralization Agents - Biomimetic approaches to stabilization of bioavailable calcium, phosphate, and fluoride ions and the localization of these ions to non-cavitated caries lesions for controlled remineralization.
Fermentable carbohydrates provide plaque bacteria with substrate for acid production.
This causes a rapid drop in plaque pH and when pH becomes less than 5.5, hydroxyapatite in enamel breaks down and calcium and phosphate ions diffuse out from the enamel.
5.5 is the “critical pH”, the point where equilibrium exists. There is no mineral dissolution and no mineral precipitation.
The plaque remains acidic for about 30-60 minutes after which normal pH is restored gradually.
The calcium and phosphate ions re-enter enamel when normal pH is restored and thus remineralization occurs.
A comprehensive lecture comparing the Types, Properties and Clinical applications of different types of artificial teeth used in denture making.
For more lectures on Dental materials follow Dr Rashid Lectures on Dental Materials on Facebook (dmbydrrashid)
Remineralization is defined as the process whereby calcium and phosphate ions are supplied from an external source to the tooth thereby, causing ion deposition into crystal voids in demineralized enamel, thus producing net mineral gain.
Remineralization Agents - Biomimetic approaches to stabilization of bioavailable calcium, phosphate, and fluoride ions and the localization of these ions to non-cavitated caries lesions for controlled remineralization.
Fermentable carbohydrates provide plaque bacteria with substrate for acid production.
This causes a rapid drop in plaque pH and when pH becomes less than 5.5, hydroxyapatite in enamel breaks down and calcium and phosphate ions diffuse out from the enamel.
5.5 is the “critical pH”, the point where equilibrium exists. There is no mineral dissolution and no mineral precipitation.
The plaque remains acidic for about 30-60 minutes after which normal pH is restored gradually.
The calcium and phosphate ions re-enter enamel when normal pH is restored and thus remineralization occurs.
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Paralleling and bisecting radiographic techniquesDr. Ritu Gupta
this is the seminar for Undergraduate students consisting of initial paralellelig and bisecting radiographic techniques, history, types, size, extraoral films, technical errors, radiographic examination in special children
Amalgam is a combination of mercury with other metals and has been used as a tooth filling material since early in the 19th century.
Alternative tooth-coloured materials are increasingly used because they look better and require less intervention.
How safe are different tooth filling materials? Are they equally effective in ensuring dental health?
Indian Dental Academy: will be one of the most relevant and exciting training center with best faculty and flexible training programs for dental professionals who wish to advance in their dental practice,Offers certified courses in Dental implants,Orthodontics,Endodontics,Cosmetic Dentistry, Prosthetic Dentistry, Periodontics and General Dentistry.
Paralleling and bisecting radiographic techniquesDr. Ritu Gupta
this is the seminar for Undergraduate students consisting of initial paralellelig and bisecting radiographic techniques, history, types, size, extraoral films, technical errors, radiographic examination in special children
Amalgam is a combination of mercury with other metals and has been used as a tooth filling material since early in the 19th century.
Alternative tooth-coloured materials are increasingly used because they look better and require less intervention.
How safe are different tooth filling materials? Are they equally effective in ensuring dental health?
Evaluation of the Concentration of Toxic Metals In Cosmetic Products In Nigeria v2zq
Evaluation of the Concentration of Toxic Metals In Cosmetic Products In Nigeria - Resources for Healthy Children www.scribd.com/doc/254613619 - For more information, Please see Organic Edible Schoolyards & Gardening with Children www.scribd.com/doc/254613963 - Gardening with Volcanic Rock Dust www.scribd.com/doc/254613846 - Double Food Production from your School Garden with Organic Tech www.scribd.com/doc/254613765 - Free School Gardening Art Posters www.scribd.com/doc/254613694 - Increase Food Production with Companion Planting in your School Garden www.scribd.com/doc/254609890 - Healthy Foods Dramatically Improves Student Academic Success www.scribd.com/doc/254613619 - City Chickens for your Organic School Garden www.scribd.com/doc/254613553 - Huerto Ecológico, Tecnologías Sostenibles, Agricultura Organica www.scribd.com/doc/254613494 - Simple Square Foot Gardening for Schools - Teacher Guide www.scribd.com/doc/254613410 - Free Organic Gardening Publications www.scribd.com/doc/254609890 ~
Lipsticks & Nail Polishes - Potential Sources of Heavy Metal in Human Body v2zq
Lipsticks & Nail Polishes - Potential Sources of Heavy Metal in Human Body - Resources for Healthy Children www.scribd.com/doc/254613619 - For more information, Please see Organic Edible Schoolyards & Gardening with Children www.scribd.com/doc/254613963 - Gardening with Volcanic Rock Dust www.scribd.com/doc/254613846 - Double Food Production from your School Garden with Organic Tech www.scribd.com/doc/254613765 - Free School Gardening Art Posters www.scribd.com/doc/254613694 - Increase Food Production with Companion Planting in your School Garden www.scribd.com/doc/254609890 - Healthy Foods Dramatically Improves Student Academic Success www.scribd.com/doc/254613619 - City Chickens for your Organic School Garden www.scribd.com/doc/254613553 - Huerto Ecológico, Tecnologías Sostenibles, Agricultura Organica www.scribd.com/doc/254613494 - Simple Square Foot Gardening for Schools - Teacher Guide www.scribd.com/doc/254613410 - Free Organic Gardening Publications www.scribd.com/doc/254609890 ~ ijpras.com
Mercury from restorations constitutes the largest non occupational source of mercury in the general population, being greater than all environmental sources combined
Heavy Metals Contamination Levels In Suya Meat Marketed In Selected Towns In ...iosrjce
IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) multidisciplinary peer-reviewed Journal with reputable academics and experts as board member. IOSR-JESTFT is designed for the prompt publication of peer-reviewed articles in all areas of subject. The journal articles will be accessed freely online.
Part 2 biocompatibilty of dental materialsDr. Ritu Gupta
this is the second part od seminar which includes biocompatibilty of various dental materials which are used in daily clinical practice including routine suture materials, rootcanal , restorative materials along with pateint photographs and case reports
This scholarly presentation delves into the array of diagnostic aids currently revolutionizing the field of endodontics. From cone-beam computed tomography (CBCT) to advanced pulp vitality tests, the talk evaluates the accuracy, efficacy, and limitations of various diagnostic tools. It will discuss their integration into a coherent diagnostic workflow, supported by the latest research and technological advancements. This presentation is crucial for endodontists, oral radiologists, postgraduate dental students, and researchers interested in leveraging precise diagnostic tools for improved clinical outcomes in endodontic care.
This presentation offers a comprehensive review of the clinical management and evidence-based approaches to endodontic emergencies. Delve into the diagnostic criteria, pathophysiology, and treatment modalities for a spectrum of endodontic conditions, including acute pulpitis, apical abscesses, and traumatic dental injuries. Utilizing the latest research and case studies, the presentation will explore key decision-making frameworks and surgical vs non-surgical interventions to optimize patient outcomes. Designed for dental professionals, postgraduate students, and researchers, this presentation aims to elevate the standard of care in the management of endodontic emergencies
This presentation provides an in-depth analysis of the application and biomechanical properties of dental composites, critically examining their role in restorative dentistry. Explore the molecular structure, mechanical characteristics, and clinical performance metrics that make composites the material of choice for a variety of dental applications. Through case studies and recent research findings, the presentation aims to elucidate the material science innovations driving advancements in this field. Recommended for dental practitioners, postgraduate students, and researchers focusing on dental materials and technologies
"Exploring Regenerative Endodontics: A Paradigm Shift in Root Canal Therapy" aims to delve into the groundbreaking approach of regenerative endodontics, which has revolutionized traditional root canal treatments. This presentation serves as a comprehensive guide for dental professionals, researchers, and students who are keen on understanding the shift towards biologically-based procedures designed to replace damaged tooth structures, including dentin and root structures, as well as cells of the pulp-dentin complex.
Key Points Covered:
Introduction to Traditional Endodontics: A brief overview of conventional root canal treatments, setting the stage for the limitations that regenerative endodontics aims to address.
Fundamentals of Regenerative Endodontics: Understand what regenerative endodontics is, its aims, and the principles guiding this new approach.
Materials and Techniques: Discover the novel materials and technologies used in regenerative endodontics including scaffolds, growth factors, and stem cells.
Clinical Applications and Benefits: Discuss various case studies and clinical trials that demonstrate the effectiveness and benefits of regenerative procedures.
Challenges and Future Prospects: A balanced view on the hurdles facing regenerative endodontics and what the future holds.
This presentation is essential viewing for anyone interested in the future of dental science and how regenerative approaches can offer effective and more natural alternatives to traditional endodontic treatments."
Feel free to modify this description to better suit your specific needs and focus points.
This presentation dwells around the listed definitions of a class 2 caries lesion and also sheds light on the various available diagnostic modalities in the present world of Endodontics
This presentation highlights the oral manifestations of each of the vitamins in general, citations of each of the references are provided within the slides.
A review on the concept of Atraumatic Restorative Treatment
it focuses on the definition, concept. indications, contraindications, history and functionality of this treatment
The second phase of a root canal treatment.
This presentation covers the most basic techniques of root canal shaping.
provides the reader with a concise overview of the big picture.
A quick and concise recap of Endodontic Instruments.
This presentation resolves the basic doubts within terminologies and provides visual conceptualization of the same.
An overview of all the radiographic considerations in the planning of dental implants. This poster covers conventional IOPA, Panoramic Radiography and lastly Cone Beam Computed Tomography.
A precise view on the various array of dental impression products available widely around us. A flowchart depicts organized classification of materials.
A concise poster depicting all the aspects one should know about autoclaves. It involves the definition, working principal, advantages, disadvantages, what to and what not to sterilize
A detailed presentation on the contemporary (presently preferred), conventional and potential modalities of caries diagnosis in the vast and developing world of dentistry.
This slide was prepared in conjunction with Dr. Janhavi Rajput & Dr. Ishaan Adhaulia.
Hope this presentation brings clarification and light to the detailed topic.
A very precise and intimate description on radiographic considerations in dental implants, since the advent of the first radiographic modality in 1905, the dental health care professionals have been striving to achieve clarity & excellence in the development & usage of dental radiographic imaging modalities.
I hope this presentation will make this wonderful topic more understandable and easier to digest in the minds of young and experienced dental health care professionals.
by Dr Ishaan Adhaulia
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
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Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
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These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
2. CONTENTS
• Introduction
• History of mercury in Dentistry
• Overview of Dental Amalgam
• Hazards of Mercury
• Forms of Mercury
• Mercury in Dentistry
• Sources of Exposure
• Pharmacokinetics of Mercury Exposure
• Regulation and Guidelines
• Management of Mercury Toxicity
• Alternatives to Dental Amalgam
• Conclusion
• References
4. HISTORY OF MERCURY USE IN DENTISTRY
Hyson Jr JM. Amalgam: Its history and perils. Journal of the California Dental Association. 2006 Mar 1;34(3):215-29.
5. AMALGAM WAR
1920 (First Amalgam
war)
1980 (Dr Hal Huggins) 1991
V/s
1926 (Alfred Stock)
Mentioned his
own accounts
of mercury
poisoning
Argued with
GV Black
Dodes JE. The amalgam controversy: an evidence-based analysis. The Journal of the American Dental Association. 2001 Mar 1;132(3):348-56.
Second amalgam war Third amalgam war
6. OVERVIEW OF DENTALAMALGAM
The most widely used restorative material Can last up-to 10 years 50% Failure: Faulty
Restoration
Composition
ADA Specification No. 1
Manufacturing
Melting Homogenization
Particle Formation Cooling and Equilibrium
Ball Milling
Thermodynamic
Equilibrium
150 – 400 ‘C
Mackenzie, L. (2021). Dental amalgam: a practical guide. Dental Update. https://doi.org/10.12968/denu.2021.48.8.607.
7. OVERVIEW OF DENTALAMALGAM
PRIMARY PHASES
Gamma (Ag3Sn) Gamma 1 (Ag2Hg3) Gamma 2 (Sn7-8Hg)
Silver – Tin alloy powder
before its mixed with Hg
When Hg mixed with
Silver-Tin alloy
Silver reacts with Hg to
form Ag2Hg2
(Gamma 1 Phase)
- DURABLE
- MAKES AMALGAM
USEFUL
Weak phase formed when
Hg reacts with Tin
(Sn8Hg)
Most prone to corrosion
and creep
Less Corrosion
Resistant
Vimal K Sikri: Textbook of Conservative and Restorative Dentistry. 1st Edition. 2019
8. ADVANTAGES OF AMALGAM
Antony K, Genser D, Hiebinger C, Windisch F. Longevity of dental amalgam in comparison to composite materials. GMS health technology assessment. 2008;4.
Durable Less Technique
Sensitive
Minimal
Placement Time
Can be used in
many clinical
situations
Corrosion
products provide
marginal seal
Less Expensive & Economical
Excellent
Compressive
strength
Proper Isolation
not necessary
Can be repaired easily
9. ROLE OF MERCURY IN AMALGAM
ACTS AS A BINDING AGENT
MERCURY RELEASES VAPOURS
RISK FOR PATIENT AND OPERATORS
Vimal K Sikri: Textbook of Conservative and Restorative Dentistry. 1st Edition. 2019
10. DOUBLE AND TRIPLE DISTILLED MERCURY
Mercury contains impurities which might interfere with dental amalgam
Fractional Distillation Boiling the mixture Collecting vapours as they condense
Less interference with
properties
More interference with
properties
Hulett GA, Minchin HD. The Distillation of Amalgams and the Purification of Mercury. Physical Review (Series I). 1905 Dec 1;21(6):388.
11. PREGNANCY & MERCURY
Dental amalgam releases mercury vapors which can be particularly harmful for the fetus
as it’s organs are not fully developed
Low Birth Weight Small Head Circumference Delayed Development
Hearing & Vision problems Neurodevelopmental Disorders
American Dental
Association
European Union US Environment
Protection Agency
World Health
Organisation
Golding J, Steer CD, Gregory S, Lowery T, Hibbeln JR, Taylor CM. Dental associations with blood mercury in pregnant women. Community dentistry and oral epidemiology. 2016 Jun;44(3):216-22.
12. HAZARDS OF MERCURY
Mercury is a heavy metal
Not Absorbed
Methylmercury disrupts essential biochemical
processes by binding to enzymes & proteins
13. FORMS OF MERCURY
Elemental Mercury
Odourless / Shiny liquid
Vaporizes at room
temperature
Used in thermometers / amalgam /
fluorescent light bulbs
Ethyl Alcohol promotes
rapid excretion of
mercury
Mahalakshmi, M. (2022). Dental materials. New Delhi, India: Jaypee Brothers Medical Publishers.
14. FORMS OF MERCURY
Inorganic Compounds
Found in batteries & skin creams
Not readily
absorbed
Can be toxic if
inhaled or ingested
MERCURY SALTS
Mahalakshmi, M. (2022). Dental materials. New Delhi, India: Jaypee Brothers Medical Publishers.
15. FORMS OF MERCURY
Organic Compounds
Methylmercury
Organomercurials
Bioaccumulation
and bio-
magnification
Can cross blood
brain barrier and
placenta
Mahalakshmi, M. (2022). Dental materials. New Delhi, India: Jaypee Brothers Medical Publishers.
16. MERCURY IN DENTISTRY
What forms of mercury do we, as Dentists, encounter in daily clinical
practice?
Elemental Mercury Methyl Mercury
Mercury Vapour
Studies have suggested that dentists could
experience adverse effects from air
concentrations of mercury as low as 14
micrograms per cubic meter, which is much
lower than the limit of 50 micrograms per
cubic meter.
Bernhoft RA. Mercury toxicity and treatment: a review of the literature. J Dent Res. 2006;85(1):1-19. doi:10.1177/0022034505283256
17. MERCURY IN DENTISTRY
Leaching from amalgam restoration is minimal. Estimates are that
450-530 amalgam surfaces would be necessary to expose an
individual to minimal toxic effect of mercury. (32 teeth 160 surfaces)
Mackert Jr JR, Berglund A. Mercury exposure from dental amalgam fillings: absorbed dose and the potential for adverse health effects. Critical Reviews in Oral Biology & Medicine. 1997 Oct;8(4):410-36.
18. SOURCES OF EXPOSURE
Improper disposal of mercury
from dental amalgam scraps
Ingestion of contaminated fish
Hg bonded to organic compounds
Most human exposure to metallic mercury comes from mercury vapor
outgassing from amalgam fillings, at a rate of 2 to 28 micrograms per
facet surface per day, with about 80% being absorbed.
Occupational exposure
- Dental Clinics / Production of
thermometers, barometers and
fluorescent lamps / gold mining /
coal fired power plants
Volcanic Eruptions
Bernhoft RA. Mercury toxicity and treatment: a review of the literature. J Dent Res. 2006;85(1):1-19. doi:10.1177/0022034505283256
19. SOURCES OF EXPOSURE
Mercury Spills
Expression of excess Hg
from Amalgam
Leakage from dispensers
Improper Storage
of scrap Amalgam
Leakage from capsule
while trituration
Langan DC, Fan PL, Hoos AA. The use of mercury in dentistry: a critical review of the recent literature. The Journal of the American Dental Association. 1987 Dec 1;115(6):867-80.
20. SOURCES OF EXPOSURE
Other
Sources
mercury vaporization from contaminated instruments placed in sterilizers
grinding of amalgam during removal of restorations
amalgam condensation with ultrasonic condensers
Studies have found little or no difference in ambient air
concentrations of mercury vapor between offices with carpeting
and those with hard floor coverings
Langan DC, Fan PL, Hoos AA. The use of mercury in dentistry: a critical review of the recent literature. The Journal of the American Dental Association. 1987 Dec 1;115(6):867-80.
V/s
21. PHARMACOKINETICS OF MERCURY EXPOSURE
INORGANIC
MERCURY
Elemental / Metallic Mercury
80% 19% 1%
> >
Mercury Vapour Sulphur containing amino acids
Metallic Mercury
Blood Brain
Barrier
Placenta
Foetal
Brain
Influences T-Cell
function
Bernhoft RA. Mercury toxicity and treatment: a review of the literature. Journal of environmental and public health. 2012 Oct;2012.
22. PHARMACOKINETICS OF MERCURY EXPOSURE
INORGANIC
MERCURY
Elemental / Metallic Mercury
Metallic Mercury Mercuric Mercury
excretion
Excretory Half
Life
Depends on
Organ
Redox
State
CNS – Hg has several years of half life
Bernhoft RA. Mercury toxicity and treatment: a review of the literature. Journal of environmental and public health. 2012 Oct;2012.
23. PHARMACOKINETICS OF MERCURY EXPOSURE
INORGANIC
MERCURY
Mercurous Mercury / Calomel
Poorly soluble / not readily absorbed
Metallic Hg Mercuric Hg
Pink disease &
Acrodynia
Bernhoft RA. Mercury toxicity and treatment: a review of the literature. Journal of environmental and public health. 2012 Oct;2012.
24. PHARMACOKINETICS OF MERCURY EXPOSURE
INORGANIC
MERCURY
Mercuric Mercury
Photographic film
development
Skin Lightening cream
Only 2% absorbed – rest
corrodes the intestine
HgCl2 Sulfhydryl groups on
erythrocytes
Metallothionein Glutathione
Mercuric Mercury Proximal Convoluted Renal Tubule
Half Life 42 days for 80%
Bernhoft RA. Mercury toxicity and treatment: a review of the literature. Journal of environmental and public health. 2012 Oct;2012.
25. PHARMACOKINETICS OF MERCURY EXPOSURE
ORGANIC MERCURY
Methyl Mercury
Major form of
organic mercury
Relatively Stable
80%
Sulfhydryl groups in cysteine
Methyl Mercury
Inorganic
Mercury
(
DEMETHYLATION
)
Half Life 70 Days ( 90% excretion in stool )
Bernhoft RA. Mercury toxicity and treatment: a review of the literature. Journal of environmental and public health. 2012 Oct;2012.
26. SYMPTOMS OF TOXICITY
INORGANIC
MERCURY
Metallic Mercury Vapour
Alters tertiary and
quaternary structure of
proteins
Binds with sulfhydryl and
selenohydryl groups
ACUTE CHRONIC
Erosive bronchitis
Bronchiolitis
Low Level Exposure
High Level Exposure
Bernhoft RA. Mercury toxicity and treatment: a review of the literature. Journal of environmental and public health. 2012 Oct;2012.
27. SYMPTOMS OF TOXICITY
INORGANIC
MERCURY
Mercuric Mercury ACUTE CHRONIC
Bernhoft RA. Mercury toxicity and treatment: a review of the literature. Journal of environmental and public health. 2012 Oct;2012.
extensive precipitation of enterocyte
intestinal cell proteins
Abdominal pain / vomiting / bloody
diarrhea
Renal tubular necrosis
Autoimmune
glomerulonephritis
Thyroid Dysfunction
Decreased
Spermatogenesis
28. SYMPTOMS OF TOXICITY
ORGANIC MERCURY
Bernhoft RA. Mercury toxicity and treatment: a review of the literature. Journal of environmental and public health. 2012 Oct;2012.
Renal tubular necrosis
Autoimmune
glomerulonephritis
Thyroid Dysfunction
Methyl & Ethyl Mercury Pre Natal Exposure Post Natal Exposure
Massive Exposures
Cerebral Palsy
Lesser Exposures
Neurodevelopmental Delays
Lesser Exposures
Paraesthesia
Moderate Exposures
Ataxia / Visual-Auditory-
Extrapyramidal impairments
Severe Exposures
Clonic Seizures
30. ACRODYNIA
Pinks Disease
Due to mercury poisoning
ACRO + DYNIA
(extremity) (pain)
• SYMPTOMS IN
CHILDREN
Red Cheeks
Transient
Rashes
Red Lips
Loss of Hair / Teeth /
Nails
31. ACRODYNIA
• TREATMENT
MAIN GOAL Remove Mercury from the body
Fixing any electrolyte loss and nutritional imbalances
Chelating Agent
2,3-dimercaptosuccinic acid
(DMSA)
Hemodialysis
Patients with Acute Kidney
Injury from Mercury Toxicity
L - Cysteine added to clear out mercury from blood
32. REGULATIONS AND GUIDELINES
Estd. In 1971, is a U.S. Federal Agency under the Dept. of Labor
Ensures safe and healthful working conditions for employees
by setting and enforcing safety standards
OSHA has established Permissible Exposure Limits (PELs) for
mercury
The current limit for mercury vapor established by OSHA is 50 mg/m3
(time-weighted average) in any 8-hour work shift over a 40-hour work
week.
https://ohsonline.com/Articles/2003/07/Mercury
34. REGULATIONS AND GUIDELINES
Staff handling mercury should be trained in
management and hygiene protocols.
The dental operatory should have good ventilation
and fresh air circulation.
The design of the operatory should allow easy cleanup after mercury spillage.
All clinic personnel should be aware of potential mercury contamination sources.
Mahalakshmi, M. (2022). Dental materials. New Delhi, India: Jaypee Brothers Medical Publishers.
35. REGULATIONS AND GUIDELINES
Preferably, use pre-capsulated alloys; avoid using
bulk alloy and mercury
Handle amalgam carefully, avoid skin contact,
and re-cap single-use capsules
Use high vacuum evacuators during the finishing and polishing of amalgam
restorations
Store scrap amalgam and excess mercury in an air-tight container with radiographic
fixer solution FIXE
R
Mahalakshmi, M. (2022). Dental materials. New Delhi, India: Jaypee Brothers Medical Publishers.
36. REGULATIONS AND GUIDELINES
Scrap and waste amalgam should be recycled
whenever possible.
Dispose of all mercury wastes and unused scrap
amalgam according to waste disposal laws.
Remove professional clothing before leaving the workplace.
Periodically monitor mercury vapor in the operatory atmosphere
using dosimeters or mercury vapor analyzers
Mahalakshmi, M. (2022). Dental materials. New Delhi, India: Jaypee Brothers Medical Publishers.
37. MANAGING A MERCURY SPILL
Determine the
extent of the spill
Block foot traffic for a 2
meter radius around the spill
Ventilate the area
https://ohsonline.com/Articles/2003/07/Mercury-Spill-Control--Cleanup.aspx?Page=1
38. MANAGING A MERCURY SPILL
Wearing protective
gloves and mask
Use a mercury spill
kit to clean the spill
Join small droplets of mercury
into a large mercury pool using
a plastic or wooden spatula
https://ohsonline.com/Articles/2003/07/Mercury-Spill-Control--Cleanup.aspx?Page=1
39. MANAGING A MERCURY SPILL
The pool is then
aspirated through
a syringe
Placed in a specially
designed container
Or if that’s unavailable, in a jar
of water before sealing it off
https://ohsonline.com/Articles/2003/07/Mercury-Spill-Control--Cleanup.aspx?Page=1
40. MANAGING A MERCURY SPILL
Mix equal parts of Sulphur and
Calcium Hydroxide powder
over the spilt mercury
Area is wiped with a
damp cloth
Dispose the cloth in a sealed
polythene bag
https://ohsonline.com/Articles/2003/07/Mercury-Spill-Control--Cleanup.aspx?Page=1
41. HOW MUCH DOES A MERCURY SPILL KIT COST?
2100 /-
(PSI)
5000/-
(U-Safe)
8200/-
(Mercury Eater)
42. MANAGING OF MERCURY VAPOR RELEASE IN DENTAL CLINIC
DURING INSERTION OF
AMALGAM
Due to high vapor pressure of mercury, surrounding air
immediately gets contaminated
Once restoration is done, immediately ventilate the room
Mercury can be recycled, gauze can be placed in non
incinerated solid waste
Amalgam hardens after insertion, less mercury vapor
Amalgam scraps to be stored in the x-ray fixer solution in
a tightly capped container
Mahalakshmi, M. (2022). Dental materials. New Delhi, India: Jaypee Brothers Medical Publishers.
43. MANAGING OF MERCURY VAPOR RELEASE IN DENTAL CLINIC
DURING FINISHING & POLISHING OF
AMALGAM
Finishing and polishing generates heat
Liquefies silver mercury (Ag2Hg3)
Process creates a Mercury rich phase
that smears over the amalgam surface
Slow polishing and water coolant helps
(melting point 127’C)
Mahalakshmi, M. (2022). Dental materials. New Delhi, India: Jaypee Brothers Medical Publishers.
44. MANAGING OF MERCURY VAPOR RELEASE IN DENTAL CLINIC
DURING REMOVAL OF AMALGAM
Removal generates heat
Liquefies silver mercury (Ag2Hg3)
This is accelerated by the heat generated by burs
Water Coolant & High Vacuum Suction
(melting point 127’C)
Mahalakshmi, M. (2022). Dental materials. New Delhi, India: Jaypee Brothers Medical Publishers.
45. MANAGING OF MERCURY VAPOR RELEASE IN DENTAL CLINIC
DURING INSTRUMENT STERILIZATION
Prior to sterilization Instruments used should be cleaned
Contaminated instruments releases mercury
on sterilization (liquid or vapor form)
Adequate Ventilation
Mahalakshmi, M. (2022). Dental materials. New Delhi, India: Jaypee Brothers Medical Publishers.
46. AMALGAM SEPARATORS
A unit installed in the dental chair apparatus to filter out
amalgam scraps and particles from wastewater
Sedimentation Filtration Centrifuge
https://www.benco.com/benco-dental-u/article/why-you-need-amalgam-separators-in-your-clinic
Khangura SD, Seal K, Esfandiari S, Quiñonez C, Mierzwinski-Urban M, Mulla SM, Laplante S, Tsoi B, Godfrey C, Weeks L, Helis E. Economic Evaluation. InComposite Resin Versus
Amalgam for Dental Restorations: A Health Technology Assessment [Internet] 2018 Mar. Canadian Agency for Drugs and Technologies in Health.
COST 200,000 Rupees or 2500$
47. MINAMATA BAY DISASTER
Industrial Disaster occurred in Japan from 1930’s to
1960’s
Industrial wastewater from the Chisso Corporation's chemical
factory, which contained methylmercury, was discharged into
Minamata Bay.
The methylmercury bioaccumulated in fish and shellfish in the
bay, a major food source for the local population.
Minamata Bay
Chisso Factory
ttps://www.med.or.jp/english/pdf/2006_03/112_118.pdf
48. MINAMATA BAY DISASTER
Minamata Disease
Protestors at the gate of
Chisso Factory
Over 2,000 people suffered from severe mercury
poisoning, known as Minamata disease.
neurological symptoms like muscle weakness, numbness in
the limbs, damage to hearing and speech
severe cases, paralysis and death.
ttps://www.med.or.jp/english/pdf/2006_03/112_118.pdf
49. MINAMATA BAY CONVENTION
January 19, 2013 – 140 countries signed up for safe use,
disposal, alternatives to mercury
Named after Minamata Bay, where the industrial
disaster took place
Primary mining, to safe storage, to the reduction of
mercury in products and industrial processes.
Specifically mentions the phase-down of dental amalgam, recognizing the need for a gradual
reduction in its use due to the challenges in immediately replacing it with alternatives.
The convention encourages member countries to promote the use of cost-effective
and environmentally sound alternatives to mercury-containing products.
https://mercuryconvention.org/sites/default/files/2021-06/Minamata-Convention-booklet-Sep2019-EN.pdf
51. ALTERNATIVES TO MERCURY
Gallium and Indium were used as alternatives to mercury in
dental amalgam
Gallium is slightly toxic after 8 hours of placement into the
cavity
Gallium Poisoning: patient progressed to dangerous episodes of
tachycardia, tremors, dyspnea, vertigo, and unexpected black-outs
Wataha JC, Nakajima H, Hanks CT, Okabe T. Correlation of cytotoxicity with elemental release from mercury-and gallium-based dental alloys in vitro. Dental Materials. 1994 Sep 1;10(5):298-303.
52. Conclusion
Amalgam is a valuable restorative material, but its use is associated
with mercury toxicity. Safer alternatives and effective waste management
practices are essential to mitigate risks. The decision of whether or not to
use amalgam fillings is a complex one that should be made on a case-by-
case basis, weighing the risks and benefits carefully.
In conclusion, amalgam is a valuable material with both risks and
benefits. The best decision for each individual patient will depend on
their specific needs and circumstances.
53. References
- Bernhoft RA. Mercury toxicity and treatment: a review of the literature. Journal of environmental and public health. 2012 Oct;2012.
- Garg N Garg AAbu Tahun I. Textbook of Operative Dentistry. 3E édition ed.; 2015.
- Roberson TM Heymann H Swift EJ Sturdevant CM. Sturdevant's Art and Science of Operative Dentistry. 5th ed. St. Louis Mo: Mosby; 2006
- Vimal K Sikri: Textbook of Conservative and Restorative Dentistry. 1st Edition. 2019
- Langford NJ, Ferner RE. Toxicity of mercury. Journal of human hypertension. 1999 Oct;13(10):651-6.
- Bernhoft RA. Mercury toxicity and treatment: a review of the literature. Journal of environmental and public health. 2012 Oct;2012.
- Hyson Jr JM. Amalgam: Its history and perils. Journal of the California Dental Association. 2006 Mar 1;34(3):215-29.
- Mackenzie, L. (2021). Dental amalgam: a practical guide. Dental Update. https://doi.org/10.12968/denu.2021.48.8.607.
- Antony K, Genser D, Hiebinger C, Windisch F. Longevity of dental amalgam in comparison to composite materials. GMS health technology assessment. 2008;4
- Golding J, Steer CD, Gregory S, Lowery T, Hibbeln JR, Taylor CM. Dental associations with blood mercury in pregnant women. Community dentistry and oral
epidemiology. 2016 Jun;44(3):216-22.
- Dodes JE. The amalgam controversy: an evidence-based analysis. The Journal of the American Dental Association. 2001 Mar 1;132(3):348-5